Re: Capirossi Completes Jerez ''Triple Crown''
Superbikes have to be based on production models, with a number of allowed modifications (a lot). Ducati would have to have a production V-4 Superbike to homologate it for racing.
The interesting thing is that they're developing a very high-end road bike supposedly based closely on the V-4 GP bike for limited production. If they build enough for homologation, they'll be likely be able to run that in WSB and AMA if they choose. It'll just be very expensive to build their race program around a totally new bike, I imagine. I also suspect that to end the 999 (or its derivatives') major-series race program might hurt its sales. And they'll only sell a handful of $50,000+ Desmosedici (GP-based) road bikes.
But, they've also been lobbying WSB to increase the displacement limit of twins to 1200cc to keep the 999 competitive in the coming years. I doubt that would happen in the AMA, but you never know these days.